1. Field of the Invention
The present invention relates to an endoscope system that picks up an image of an inside of a subject with image pickup means.
2. Description of the Related Art
In recent years, an endoscope including an insertion section insertable into a body cavity and the like has been widely used in a medical field and the like.
On the other hand, when the endoscope is inserted into a lumen organ complexly branching like a bronchus in the body cavity to examine (a diseased tissue of) a target region of the periphery side of the lumen organ or perform a biopsy or treatment by a treatment instrument, it is sometimes difficult to introduce an insertion section distal end near the target region using only an endoscopic image obtained when the endoscope is inserted.
Therefore, a system and an apparatus for supporting operation for introducing the insertion section distal end of the endoscope near the target region have been proposed.
For example, a medical image observation supporting apparatus of International Publication No. 2007-129493 cited as a first conventional example discloses a configuration including a CT-image-data capturing section, a CT-image-data storing section, an information extracting section, an anatomical information database, a visual-point-position/visual-line-direction setting section, a lumen-organ-image generating section, an anatomical-name-information generating section, a branch designating section, an image combining and displaying section, and a user-I/F control section. The visual-point-position/visual-line-direction setting section locks on, on the basis of structure information of a lumen organ extracted by the information extracting section, a visual point in a substantially center axis of the lumen organ and sets a visual point position and a visual line direction for observing an external appearance of the lumen organ.
A medical apparatus of Japanese Patent Application Laid-Open Publication No. 2009-279250 cited as a second conventional example includes virtual-endoscopic-image generating means for generating, from three-dimensional image data of a bronchus acquired in advance, virtual endoscopic images from a plurality of different visual line positions, image retrieving means for retrieving a virtual endoscopic image having high similarity to a real image, reference-point setting means for setting a reference point on the basis of a position of a visual line of the virtual endoscopic image having the high similarity, relative-position calculating means for calculating a relative position of a treatment instrument with respect to the reference point, movement detecting means for detecting movement of the reference point or the bronchus, and position correcting means for correcting the relative position according to the movement of the reference point or the bronchus.
When a position of an insertion section distal end of an endoscope is estimated, the estimation is performed by comparison of an endoscopic image (a real image) picked up by image pickup means of the endoscope and a virtual endoscopic image (a virtual image) generated on the basis of three-dimensional data of a lumen organ by CT. Therefore, first, alignment by the comparison of both the images is performed.
When accuracy of the estimation of the position is deteriorated, re-alignment for setting the endoscope in a state in which predetermined accuracy can be secured is necessary.
The first conventional example discloses a viewpoint of coordinate-converting an endoscope distal end position into a three-dimensional image and comparing a distance between the endoscope distal end position and a core line and a viewpoint of comparing a real image (an endoscopic image) and a virtual image (a virtual endoscopic image) of a branch section and also discloses recording of feature information and the like of the branch section.